For stamping the servo signals onto the magnetic tapes by using a servo writer, the servo signals are recorded while the magnetic tapes are passing through the magnetic head installed in the servo writer. Since the recorded servo signals are used for the reference tracks to which the operation of the magnetic recording heads or the magnetic reproducing heads are adjusted. Therefore it is quite important to precisely record the servo signals in the position relative to the side edges of the magnetic tapes.
A prior art in a published patent show an example of the servo signal recording technology as shown in the reference 1. This existing technology is to use a combination of a tape guide and a bias mechanism of air pressure so that the tape is slightly floated and guided in compliance to the tape guide. This mechanical construction of the guiding system suppresses the tape lateral vibration against the tape passing to the tape take-up reels.
Reference 1                Published Japanese Patent Application: paragraphs 0008-0021 and FIG. 1, JP, 2001-35048, A (1999)        
Reference 2                U.S. Pat. No. 6,433,959 B1        
However, in this existing technology, it is necessary to control the air pressure for the bias mechanism. The constant air pressure does not guarantee at the stable tape passing on the tape bias mechanism due to the compressiveness and the dynamic vibration of the air flow and the elasticity of the magnetic tape material.
For the case of the poor alignment of the tape passing direction against the guiding mechanism, an edge of the tape is pushed against the tape guide and damaged by the rubbing with the guide, that is, so-called “edge damage”.
The present invention has an advantage to suppress the lateral vibration for the tapes passing through the servo signal recording head to be wound to the tape reels. It is preferred to suppress the lateral vibration potentially generated in the servo writer. Then the passing tapes have no edge damages and stable tracks of recorded servo signals are obtained in the magnetic tapes. In addition, the present invention provides a servo writer that records stable servo signals by the magnetic head assembly.